Exact match. Not showing close matches.
'[EE]: Driving an LED with +3V and a +5V logic PIN'
Robert E. Griffith
Is there anything wrong with this?
+5V Logic output ---.
When the output is high, the LED will be reverse biased by around 2V, which
is within its spec (5V).
The reason I want to do this is that the Rabbit Core Module (uP + Memory +
Ethernet) I am using is a 3V device, but on board, it has a 5V out charge
pump for its Ethernet chip. I am using that chip’s link status output to
drive an LED on my board which only has 3V availale.
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics
|Should be just fine. I have been doing this for years now on some of my
display cards with a whole bunch of LEDs on board - the LED drivers are
74hc595 shift registers powered from the 5V logic supply but the LEDs
operate from a dedicated 4.0V or 3.3V simple switcher SMPS. Thousands of
cards in operation for several years with no LED failures.
At 01:43 PM 10/15/02 -0400, Robert E. Griffith wrote:
>When the output is high, the LED will be reverse biased by around 2V, which
>is within its spec (5V).
Dwayne Reid <planet.eon.net> dwayner
Trinity Electronics Systems Ltd Edmonton, AB, CANADA
(780) 489-3199 voice (780) 487-6397 fax
Celebrating 18 years of Engineering Innovation (1984 - 2002)
.-. .-. .-. .-. .-. .-. .-. .-. .-. .-
`-' `-' `-' `-' `-' `-' `-' `-' `-'
Do NOT send unsolicited commercial email to this email address.
This message neither grants consent to receive unsolicited
commercial email nor is intended to solicit commercial email.
http://www.piclist.com hint: The PICList is archived three different
ways. See http://www.piclist.com/#archives for details.
More... (looser matching)
- Last day of these posts
- In 2002
, 2003 only
- New search...